We propose to continue and strengthen the existing Chinese Longitudinal Healthy Longevity Survey (CLHLS) study carried out in 1998, 2000, and 2002. We plan to gather more extensive questionnaire data through conducting two more follow-up waves in 2005 and 2008 with about 7,450, 7,500, and 7,130 interviews to centenarians, non-agenarians, and octogenarians, respectively. Relatively comprehensive data on mortality and health status before dying for the 10,382 oldest-old interviewees aged 80-110 who will have died between 2002 and 2008 waves will be collected through interviewing a close family member of the deceased elders. In the 2005 and 2008 waves, we will also conduct follow-up interviews with about 1,000 younger elders aged 65-79 and about 1,000 elderly interviewees' adult children aged 35-71. As was done in 1998, 2000, and 2002, this largest longitudinal survey study on oldest-old with sub-samples of younger elderly and adult children will be conducted in randomly selected half of the counties/cities of 22 provinces; the population in those provinces constitutes about 85% of the total population of China. This application seeks NIA funds to support the main sample of the oldest-old aged 80-110; the sub-sample of the younger elders and adult children will be covered by Chinese sources. Using conventional and advanced demographic/statistical methods, we plan to analyze the CLHLS data with substantially increased statistical power to be achieved from two more follow-up waves in 2005 and 2008. We aim to gain a better understanding of patterns, trends of change in disability, risk factors and determinants of healthy survival, disability, mortality, and extent of suffering before dying at old ages, especially among the oldest-old. We plan to continue to archive the CLHLS data sets and make them userfriendly and widely available to scientists outside and inside of China. As in 1997-2004, this project will continue to be part of the NIA-supported research network on healthy longevity coordinated by James W. Vaupel and Cindy Owens at Duke University.